scholarly journals Bioinspired Dielectric Film with Superior Mechanical Properties and Ultrahigh Electric Breakdown Strength Made from Aramid Nanofibers and Alumina Nanoplates

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3093
Author(s):  
Qiu-Wanyu Qing ◽  
Cheng-Mei Wei ◽  
Qi-Han Li ◽  
Rui Liu ◽  
Zong-Xi Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Hydrogen Bonding ◽  
Composite Film ◽  
Breakdown Strength ◽  
Composite Films ◽  
Electrical Equipment ◽  
Electric Breakdown ◽  
Excellent Thermal Stability ◽  
Practical Applications ◽  
Al2o3 Composite

Materials with excellent thermal stability, mechanical, and insulating properties are highly desirable for electrical equipment with high voltage and high power. However, simultaneously integrating these performance portfolios into a single material remains a great challenge. Here, we describe a new strategy to prepare composite film by combining one-dimensional (1D) rigid aramid nanofiber (ANF) with 2D alumina (Al2O3) nanoplates using the carboxylated chitosan acting as hydrogen bonding donors as well as soft interlocking agent. A biomimetic nacreous ‘brick-and-mortar’ structure with a 3D hydrogen bonding network is constructed in the obtained ANF/chitosan/Al2O3 composite films, which provides the composite films with exceptional mechanical and dielectric properties. The ANF/chitosan/Al2O3 composite film exhibits an ultrahigh electric breakdown strength of 320.1 kV/mm at 15 wt % Al2O3 loading, which is 50.6% higher than that of the neat ANF film. Meanwhile, a large elongation at break of 17.22% is achieved for the composite film, integrated with high tensile strength (~233 MPa), low dielectric loss (<0.02), and remarkable thermal stability. These findings shed new light on the fabrication of multifunctional insulating materials and broaden their practical applications in the field of advanced electrics and electrical devices.

The Effects of Coupling Agents on the Electrical Properties of Polyimide/TiO2 Hybrid Films

2014 ◽  
Vol 556-562 ◽  
pp. 371-374
Author(s):  
Kai Yan ◽  
Xiao Xu Liu
Keyword(s):  
Composite Film ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Electric Breakdown ◽  
Future Application ◽  
Breakdown Field ◽  
Coupling Agents ◽  
Hybrid Films ◽  
Simple Method

Polyamides (PI)-matrix composite films with inorganic nanoTiO2 have been fabricated by employing in situ polymerization. Before addition, TiO2 particles were firstly modified with coupling agents (KH550). The electric breakdown strength and micromorphology of hybrid films were characterized and investigated. Results indicated that nanoTiO2 particles were homogeneously dispersed in the PI matrix for the addition of coupling agents and the electric breakdown strength of PI/TiO2 composite films with KH550 were better than unmodified PI composite film. The breakdown field strength and tensile modulus of PI composite film with the inorganic content of 5 wt% were 200.1 (KV/mm). So the using coupling agent can effectively improve the compatibility and the homogenous dispersion of nanoTiO2 particles in PI matrix. Meanwhile, the procedure described here offers an effective and simple method to produce PI/TiO2 with excellent electrical needed for future application in electrical engineering field.

scholarly journals The Effects of Coupling Agents on the Properties of Polyimide/Nano-Al2O3Three-Layer Hybrid Films

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Lizhu Liu ◽  
Ling Weng ◽  
Yuxia Song ◽  
Lin Gao ◽  
Qingquan Lei
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Composite Film ◽  
Breakdown Strength ◽  
Composite Films ◽  
Coupling Agents ◽  
Hybrid Films ◽  
Mechanical Method ◽  
Elongation At Break

PI/nano-Al2O3hybrid films were prepared by ultrasonic-mechanical method. Before addition, nano-Al2O3particles were firstly modified with different coupling agents. The micromorphology, thermal stability, mechanical properties, and electric breakdown strength of hybrid films were characterized and investigated. Results indicated that nano-Al2O3particles were homogeneously dispersed in the PI matrix by the addition of coupling agents. The thermal stability and mechanical properties of PI/nano-Al2O3composite films with KH550 were the best. The tensile strength and elongation at break of PI composite film were 119.1 MPa and 19.1%, which were 14.2% and 78.5% higher than unmodified PI composite film, respectively.

scholarly journals Boosting Performance of Self-Polarized Fully Printed Piezoelectric Nanogenerators via Modulated Strength of Hydrogen Bonding Interactions

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1908
Author(s):  
Hai Li ◽  
Sooman Lim
Keyword(s):  
Hydrogen Bonding ◽  
Composite Film ◽  
High Performance ◽  
Composite Films ◽  
Β Phase ◽  
Hydrogen Bonding Interactions ◽  
Barium Titanate Nanoparticles ◽  
Surface Modified ◽  
Piezoelectric Devices ◽  
Piezoelectric Nanogenerators

Self-polarized piezoelectric devices have attracted significant interest owing to their fabrication processes with low energy consumption. Herein, novel poling-free piezoelectric nanogenerators (PENGs) based on self-polarized polyvinylidene difluoride (PVDF) induced by the incorporation of different surface-modified barium titanate nanoparticles (BTO NPs) were prepared via a fully printing process. To reveal the effect of intermolecular interactions between PVDF and NP surface groups, BTO NPs were modified with hydrophilic polydopamine (PDA) and hydrophobic 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) to yield PDA-BTO and PFD-BTO, respectively. This study demonstrates that the stronger hydrogen bonding interactions existed in PFD-BTO/PVDF composite film comparative to the PDA-BTO/PVDF composite film induced the higher β-phase formation (90%), which was evidenced by the XRD, FTIR and DSC results, as well as led to a better dispersion of NPs and improved mechanical properties of composite films. Consequently, PFD-BTO/PVDF-based PENGs without electric poling exhibited a significantly improved output voltage of 5.9 V and power density of 102 μW cm−3, which was 1.8 and 2.9 times higher than that of PDA-BTO/PVDF-based PENGs, respectively. This study provides a promising approach for advancing the search for high-performance, self-polarized PENGs in next-generation electric and electronic industries.

Enhanced thermal conductivity of polyimide composite film filled with hybrid fillers

2021 ◽  
pp. 095400832110003
Author(s):  
Ruiyi Li ◽  
Chengcheng Ding ◽  
Juan Yu ◽  
Xiaodong Wang ◽  
Pei Huang
Keyword(s):  
Thermal Conductivity ◽  
Composite Film ◽  
Hexagonal Boron Nitride ◽  
Composite Films ◽  
Resistance Index ◽  
Reference Value ◽  
Residual Rate ◽  
Practical Applications ◽  
Hybrid Fillers ◽  
The Matrix

In this article, the polyimide (PI) composite films with synergistically improving thermal conductivity were prepared by adding a few graphene nanoplatelets (GNP) and various hexagonal boron nitride (h-BN) contents into the PI matrix. The thermal conductivity of PI composite film with 1 wt% GNP and 30 wt% h-BN content was 1.21 W(m·k)− 1, which was higher than that of the PI composite film with 30 wt% h-BN content (0.45 W(m·k)− 1), the synergistic efficiency of GNP under various h-BN content (10 wt%, 20 wt%, and 30 wt%) were 1.70, 2.71, and 3.09, respectively. And it was found that the increased h-BN content can suppress the dielectric properties caused by GNP in the matrix. The dielectric permittivity and dielectric loss tangent of 1 wt% GNP/PI composite film were 10.69, 0.661 at 103 Hz, respectively, and that of the 30 wt% h-BN + GNP/PI composite film were 4.29 and 0.1367, respectively. Moreover, the mechanical properties of the PI composite film were suitable for practical applications. And the heat resistance index and the residual rate at 700°C of PI composite film increased to 326.8°C, 74.43%, respectively, and these of PI film were 292.6°C and 59.26%. Thus, it may provide a reference value for applying the filler hybridization/PI film in the electronic packaging materials.

The Preparation and Property Research on Laponite-Poly (L-Lactide) Composite Film

2013 ◽  
Vol 750-752 ◽  
pp. 1919-1923 ◽  
Author(s):  
Guo Xian Zhou ◽  
Ming Wei Yuan ◽  
Lin Jiang ◽  
Ming Long Yuan ◽  
Hong Li Li
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Composite Film ◽  
Composite Films ◽  
Complexing Agent ◽  
Solution Blending ◽  
Method Of Solution ◽  
Thermal Stability Of ◽  
Scanning Electron

The laponite-poly (L-lactide) composite films are prepared by the method of solution blending with polylactide (PLA) and laponite. The result shows that the homogeneous and smooth composite film is prepared with 1, 4-dioxane. Thermogravimetry analysis (TG) and tensile strength studies demonstrate that the thermal stability and tensile strength are improved with the laponite added. The scanning electron microscopy (SEM) measurement indicates that the pores of composite films get uniform and network structure is more and more compact with compared to pure PLA film. The present study reveals that the laponite as a complexing agent can improve the mechanical properties and thermal stability of PLA.

Ultrahigh energy density with excellent thermal stability in lead-free multilayer ceramic capacitors via composite strategy design

2021 ◽  
Author(s):  
Peiyao Zhao ◽  
Lingling Chen ◽  
Longtu Li ◽  
Xiaohui Wang
Keyword(s):  
Thermal Stability ◽  
Energy Density ◽  
Low Energy ◽  
Electronic Systems ◽  
Ultrahigh Energy ◽  
Multilayer Ceramic Capacitors ◽  
Excellent Thermal Stability ◽  
Practical Applications ◽  
Multilayer Ceramic ◽  
Strategy Design

Dielectric capacitor has received growing interest for advanced electrical and electronic systems. However, the low energy density and poor thermal stability at high temperature severely hinder its practical applications. Herein,...

scholarly journals Mechanically Robust Flexible Multilayer Aramid Nanofibers and MXene Film for High-Performance Electromagnetic Interference Shielding and Thermal Insulation

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3041
Author(s):  
Jun Zhou ◽  
Junsheng Yu ◽  
Dongyu Bai ◽  
Huili Liu ◽  
Lu Li
Keyword(s):  
Mechanical Properties ◽  
Composite Film ◽  
Electromagnetic Interference ◽  
Multilayer Structure ◽  
High Performance ◽  
Composite Films ◽  
Next Generation ◽  
Shielding Effectiveness ◽  
Breaking Strain ◽  
Practical Applications

In order to overcome the various defects caused by the limitations of solid metal as a shielding material, the development of electromagnetic shielding materials with flexibility and excellent mechanical properties is of great significance for the next generation of intelligent electronic devices. Here, the aramid nanofiber/Ti3C2Tx MXene (ANF/MXene) composite films with multilayer structure were successfully prepared through a simple alternate vacuum-assisted filtration (AVAF) process. With the intervention of the ANF layer, the multilayer-structure film exhibits excellent mechanical properties. The ANF2/MXene1 composite film exhibits a tensile strength of 177.7 MPa and a breaking strain of 12.6%. In addition, the ANF5/MXene4 composite film with a thickness of only 30 μm exhibits an electromagnetic interference (EMI) shielding efficiency of 37.5 dB and a high EMI-specific shielding effectiveness value accounting for thickness (SSE/t) of 4718 dB·cm2 g−1. Moreover, the composite film was excellent in heat-insulation performance and in avoiding light-to-heat conversion. No burning sensation was produced on the surface of the film with a thickness of only 100 μm at a high temperature of 130 °C. Furthermore, the surface of the film was only mild when touched under simulated sunlight. Therefore, our multilayer-structure film has potential significance in practical applications such as next-generation smart electronic equipment, communications, and military applications.

Fabrication of Composite Films Based on Chitosan and Vegetable-Tanned Collagen Fibers Crosslinked with Genipin

2021 ◽  
Vol 116 (10) ◽  
Author(s):  
Jie Liu ◽  
Yanchun Liu ◽  
Eleanor M. Brown ◽  
Zhengxin Ma ◽  
Cheng-Kung Liu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Water Vapor ◽  
Composite Film ◽  
Composite Films ◽  
Value Added ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Leather Industry ◽  
Compact Structure

The leather industry generates considerable amounts of solid waste and raises many environmental concerns during its disposal. The presence of collagen in these wastes provides a potential protein source for the fabrication of bio-based value-added products. Herein, a novel composite film was fabricated by incorporating vegetable-tanned collagen fiber (VCF), a mechanically ground powder-like leather waste, into a chitosan matrix and crosslinked with genipin. The obtained composite film showed a compact structure and the hydrogen bonding interactions were confirmed by FTIR analysis, indicating a good compatibility between chitosan and VCF. The optical properties, water absorption capacity, thermal stability, water vapor permeability and mechanical properties of the composite films were characterized. The incorporation of VCF into chitosan led to significant decreases in opacity and solubility of the films. At the same time, the mechanical properties, water vapor permeability and thermal stability of the films were improved. The composite film exhibited antibacterial activity against food-borne pathogens. Results from this research indicated the potential of the genipin-crosslinked chitosan/VCF composites for applications in antimicrobial packaging. 

Design and development of HMS@ZIF-8/fluorinated polybenzoxazole composite films with excellent low-k performance, mechanical properties and thermal stability

2020 ◽  
Vol 8 (22) ◽  
pp. 7476-7484 ◽  
Author(s):  
Xudong Zhou ◽  
Xiaoyun Liu ◽  
Zhongkai Cui ◽  
Jinlou Gu ◽  
Shaoliang Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Composite Film ◽  
Composite Films ◽  
Design And Development ◽  
Hollow Silica ◽  
New Type ◽  
Low K

A new-type of hollow silica@ZIF-8 (HMS@ZIF-8) particle was successfully designed, fabricated and introduced into the fluorinated polybenzoxazole (6FPBO) matrix to prepare the HMS@ZIF-8/6FPBO composite film.

Fabrication and characterization of polyimide/Al2O3 composite films via surface modification and ion exchange technique

2016 ◽  
Vol 45 (1) ◽  
pp. 30-37 ◽  
Author(s):  
M.Y. Zhang ◽  
L.Z. Liu ◽  
L. Weng ◽  
W.W. Cui ◽  
K.S. Hui
Keyword(s):  
Surface Modification ◽  
Ion Exchange ◽  
Breakdown Strength ◽  
Composite Films ◽  
Annealing Treatment ◽  
Ambient Air ◽  
Ammonia Solution ◽  
Excellent Thermal Stability ◽  
Content Type ◽  
General Importance

Purpose – The aim of this study was to fabricate polyimide (PI)/Al2O3 composite films via surface modification and ion exchange techniques, and examine their properties. Design/methodology/approach – The method involves hydrolyzing the PI film double surface layers in an aqueous potassium hydroxide (KOH) solution and incorporating aluminium ions (Al3+) into the hydrolyzed layers of the PI film via subsequent ion exchange, followed by a treatment of the Al3+-loaded PI films with an aqueous ammonia solution, which leads to the formation of Al(OH)3 in the surface-modified layers. After a final thermal annealing treatment in ambient air, the Al(OH)3 decomposes to Al2O3, and forms composite layers on both surfaces of the re-imidized PI film. Findings – The PI/Al2O3 composite film obtained with a 6 hours of KOH treatment exhibited excellent thermal stability, good mechanical properties and better electric breakdown strength and corona-resistance properties than the pristine PI film. Practical implications – The method for obtaining the composite films in this paper is worth consideration, but additional research will be needed. Furthermore, this method is of general importance for the fabrication of composite PI films with tailored properties. Originality/value – This study showed that surface modification and ion-exchange techniques are powerful methodologies for the fabrication of PI/Al2O3 composite films.

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